EPA Extends Comment Period On Sulfonylurea Herbicide Product Labels

EPA Extends Comment Period On Sulfonylurea Herbicide Product Labels

EPA has extended the comment period until Nov. 14 on a Proposed Interim Decision (PID) for regulating the class of herbicides known as sulfonylureas. Sulfonylurea herbicides are currently used on millions of acres in the United States.


Using the most conservative models and endpoints to predict exposures of concern, the agency has determined that risks to non-target plants warrant additional label restrictions when products are applied either by ground or air. To protect against the potential damage that these models predict, EPA is proposing that labels would be required to instruct that:

  • All applications of products which include a sulfonylurea must be made using equipment delivering an extremely coarse droplet size.
  • All applications would be prohibited when wind speeds at the application site exceed 10 miles per hour.
  • When making aerial applications maximum boom lengths, swath displacement, and nozzle orientation would be defined and made mandatory.
  • When making ground application the distance between the spray nozzle and the ground or crop canopy would be restricted to no more than 2 feet.
  • Tank mixes with different mode-of-action and herbicides such as glyphosate would be prohibited if the extremely course droplet size is required as these applications generally require small droplet size to be efficacious.

There is general support for spray drift advisory language on labels but placing specific restrictions on equipment types, configurations, and their operating parameters may discourage applicators from investing in newer technologies designed to better manage drift, according to a press release from the Agricultural Retailers Association. The economic investment that applicators may be required to make in order to continue to apply sulfonylureas appears to have been overlooked.

EPA is seeking comments on all sulfonylurea product labels. The agency has established a different Public Docket for each of the 22 sulfonylureas currently registered for use in the U.S. The complete PID may be found in any of the 22 Dockets and comments applicable to any sulfonylurea may be submitted to any one of the dockets.